System of electrical distribution.



No. 880,705. PATENTED MAR. 3, 1908.

J. L. WOODBRIDGE.

SYSTEM OF ELECTRICAL DISTRIBUTION.

APPLICATION FILED AUG. 30,1905.

2 SHEETS-SHEET 1,

A TTOIMEY.

SYSTEM OF ELECTRICAL DISTRIBUTION.

Specification of Letters Patent.

Patented March 3, 1908.

Application filed August 301 1905- Serial No. 276.351.

To all whom 'it may concern:

lie it known that l, .losrn'n lms'rlcn. \Vooo- BRIDGE, a citizen of the United States, resi d ing at Philadelphia, in the county of lhiladelphia and State of Pennsylvania, have invented a certain new and useful System of .lfilectrical Distribution, of which the following is a specification.

My invention relates to those systems of electrical generation and distribution in which both direct and alternating currents are employed, and its principal object is to provide simple and etlicient means for converting either form of electrical energy into the other and for controlling their relations.

To these and other ends hereinafter set forth the invention comprises the improvements to be presently described and finally claimed.

The nature, charactmistic features and scope of my invention will be more fully understood from the following description taken in connection with the accompanying drawings forming part hereof and in which Figure 1 represents apparatus embodying features of the invention adapted to transform energy from direct to alternating current, while Fig. 2, illustrates similar apparatus arranged to transfer energy in either direction between an alternatingcurrent and a direct current circuit.

In Fig. 1, alternating current taken from the same winding to which the commutator and directcurrent brushes are connected, while in Fig. 2, two windings in inductive relation, are shown. \Yhen operating in parallel with an alternating current source, as in Fig. 2, the revolving brushes must be driven by a synchronous motor. This motor as shown, is of the revolving field type, current for field excitation being taken from the circuit X Y and delivered to the field windings by collector rings on the shaft 14, in the usual manner. \Vith a direct current source only, as in Fig. 1, a direct current motor must be used.

In the drawings G, is a source of direct cur rent electrical energy, as for example a direct current generator, to whose terminals are connected respectively the conductors as, 1

B, is a piece of apparatus embodying features of the invention analogous to a trans former or converter. This piece of apparatus will now be described in connection with the drawing.

Q, is a magnetic circuit shown in the draw- 12, and 13.

ings a circular rim provided with openings t, to receive windings.

4, is a winding cunbracing the inner portion of the rim Q, and connected to a commutator ll, in the usual manner. For siniplicity only a few of the. connections from this winding to its commutator are shown. To this winding in Fig. 1 are connected at points 7, t) and 8, respectively the three conductors 1, 2, 3, which constitutethe alternating current consumption circuit.

in Fig. .2, a second winding 5, is shown, embracing the outer portion of the rim, to which the alternating current circuit 1, 2, 2%, is connected, instead of to the winding 4.

The magnetic circuit Q, ,with its windings and the commutator are. all stationary.

Bearing on the commutator are two pairs of brushes, 12, 13, and 5t) and 51, which are carried on a shaft 14, concentric with the commutator and arranged to be driven as by the dire t current motor 15'" in Fig. 1, or the synchronous motor m in Fig. 2. This motor as shown is of the revolving tield type, current for 'lield excitation being taken from the circuit :1' 1 and delivered to the field windings by collector rings on the shaft 14 in the usual manner.

The brushes 12 and 13 are insulated from the shaft 14, but are connected respectively to collector rings 18 and 19 carried on said shaft. To these collector rings the circuit a: y is connected by suitable brushes.

The brushes 5t) and 51 bear upon the corninutator 11, at points 90 from the brushes These brushes 50 and 51 are also insulated from the shaft 141, but are electrically connccted to each other by a conductor of low resistance 6, "11.0. short circuited.

The operation of this apparatus is as follows: The shaft 14 is rotated by the motor 15*, in Fig. 1, or the motor m, in Fig. 2 thereby driving the brushes 12, 13, 5t) and 51 around the commutator 1 1. tween the direct current circuit a: y and the collector rings 18 and 19, thus applying a direct current electro-motive force to the brushes 12 and. 13. The tendency of this direct current electro-nmtiVe force will be to send current through the winding 4, between the brushes 12 and. 13, and .it' not opposed by a suitable counter electro-inotive force, this current would be excessive. Such a'counter electro-motive-force will, however, be produced by means of the short circuited Connection is made be- -field in a direction corresponding with the line of contact of said .brushes and rotatin with them. This field by its rotation will produce a small electro-motive force at right angles to itself, and therefore at the short circuitedbrushes 50 and 51. This electromotive force will send current of considerable magnitude between these short circuited brushes and in the winding 4, creating a strong magnetic field in a direction corresponding with the line of contact of the brushes 50 and 51, and this field will in turn, create the necessary counter-electromotiveforce between the brushes 12 and. 13, thus preventing the flow of any more current between these brushes 12 and 13 than is necessary to maintain the field strength and the counter electro-motive-force as above described. The rotating field will now produce an alternating electro-motive force in the winding 4, of Flg. 1, or in both windings of Fig. 2, from which alternating current may then be taken by the consumption circuit 1, 2,'"and 3.

In Fig. 2 A, is a source of three phase alternating electro-motive force connected to the consumption circuit which may supply a portion of the energy demanded. Or it may supply the entire alternating current load and in addition reverse the operation of the transformer B causing it to convert alter nating current into direct current for supplying the demand on the direct current working circuit as at O. p

To summarize it will be observed from the above description that the converting apparatus shown in the drawi s consists essenwindings and a commutator, upon which commutator bear. two pair of brushes displaced at an angle of 90, each'pair connected y an independent conducting circuit with means for producing relative rotationof brushes and commutator, and further that whenever a flow of alternatin current is inducedby whatever cause, in t e windings, in proper phase relation to one pair of brushes, the resulting flow of current between this pair will by its effect on the magnetic circuit, cause a flow of direct current between the other pair of brushes, and this latter flow will be approximately proportional to the flow of alternating current first mentioned. Or, if a flow of direct current is induced between one pair of brushes, such flow will, by its efiect on the magnetic circuit, cause a flow of direct current between the other air of brushes, and this latter flow b its e ect on the magnetic circuit, will pro uce an alternating electro-motive. force in the windi and a flow of alternating current from t e latter if connected to a suitable alternating current circuit. Furthermore, it is an inherent characteristic of the converting a paratus herein described that when use to produce in a circuit connecting one pair of )rushes a flow of direct current corresponding to a flow of alternating current in the windings, the flow of direct current may be made proportional to any particular phase component of the alternating current by the proper adjustment of the brushes with reference to the phase relation of the synchronous motor; that is, the adjustment maybe such that the direct current will be proportional to the energy component or to the wattless component of the alternating current, or to 1 any other component intermediate in phase relation.

It will be obvious to those skilled in the art to which the invention relates that modifications may be made in details without departing from the spirit thereof, hence the invention is not limited further than the prior state of the art may require, but

Having thus described the nature and objects of my invention what I claim as new and desire to secure by Letters Patent is 1. In combination a magnetic circuit of which all parts are relatively fixed, a winding in inductive relation thereto, a commutator connected to said windin one set of brushes for said commutator adapted for connection to a direct current circuit, another set of brushes electrically interconnected and ada ted to produce a displaced magnetic fiekFin said magnetic circuit, and means for producing relative rotation of brushes and commutator. y f

2. In combination a magnetic circuit of which all parts are relatively fixed, a winding in inductlve relation thereto, a commutator connected to said winding, brushes for said commutator adapted for connection to a direct current circuit and direct current means for producing a rotating magnetic field in said magnetic circuit, displaced with respect to the point of contact of said brushes.

3. Incombination a magnetic circuit all parts of which are relatively fixed, a winding 1n inductive relation thereto, alternatin current connections for said winding, and irect current means for producing in said m source of direct current electro-motive-force, and direct current means for roducing in the winding an electro-motiveorce counter to that of the source.

5. In combination a ma netic circuit, of which all parts are relative y fixed, a winding in inductive relation thereto, a commutator connected to said winding, and commutator brushes whereof some are short circuited and others are adapted for connection to direct current lines.

6. In combination a winding, alternating current connections thereto, and direct cur rent means for producing therein a rotating magnetic field, said means including a commutator and brushes of which some are adapted for connection to a source of direct current electro-motive-force while others are displaced with respect to the first and short circuited.

7. In combination a winding provided with a commutator, a second winding in inductive relation to the first winding and provided with alternating current connections, commutator brushes whereof some are short circuited and others are adapted for connection to direct current lines, and means for producing rotation between the brushes and commutator, substantially as described.

8. In apparatus for the inductive transformation of electrical energy from one form to another, the combination with a direct current source of a plurality of conducting coils in inductive relation, a commutator connected to some of said coils, a set of brushes for said commutator arranged to permit current to flow from the source through the coils to establish a magnetic field within said coils, means for producing relative motion between brushes and commutator to rotate said field with respect to said coils, and means including a second set of brushes electrically interconnected and maintained at an angular displacement from the first set and arranged to permit a flow of current caused by the electro-motive-force developed by the rotation of said field and thereby produce a second rotating field within said coils and a counter-electro-motive-force opposed to that of the source.

9. In combination a winding on a magnetic circuit, a commutator connected to said winding, 9. set of brushes bearing on the commutator, a sourceof direct current electro-motive-force connected to the brushes, means for producin relative rotation of cornmutator and brus es, and means dependent upon the magnetic flux produced b the flow of current from the source throug the winding including a second set of electrically interconnected brushes maintained at an angular displacement from the first set for producing in the winding a second relatively rotating magnetic flux and an electro-motiveforce counter to that of the source.

10. In combination a winding on a magnetic circuit, a commutator connected to said winding, a set of brushes bearing on the commutator, a source of direct current electro-motive-force connected to the brushes means for producing relative rotation of commutator and brushes, means dependent upon the magnetic flux produced by the flow oficurrent from the source through the winding including a second set of electrically interconnected brushes maintained at an angular displacement from the first set for producing in the winding a second relatively rotating magnetic flux and an electro-motive-force counter to that of the source, and means for derivin from. the inductive effect of one of the reIatively rotat-- in magnetic fluxes electrical energ in a dierent form from that supplied y the source.

11. In combination a ma netic circuit all parts of which are relativeIy fixed, a plurality of conducting coils in inductive relation to said magnetic circuit, alternating current connections to some of said coils, a commutator connected to some of said coils, two sets of brushes for said commutator, means for connecting the opposite brushesof one set to an electrical circuit, an independent electrical circuit connecting the opposite brushes of the other set, and means for producing relative rotation of commutator and brushes. 12. In combination a magnetic circuit, conducting coils in inductive relation to said circuit, a commutator connected to some of said coils, means for inducing a flow of alternating current through some of said coils, two sets of brushes for said commutator electrically displaced from each other, each set electrically interconnected by an independent circuit, and means for producing relative rotation of commutator and brushes.

In testimony whereof I have hereunto signed my name.

JOSEPH LESTER WOODBRIDGI'I. 

